ffmpeg视频速度改变无法使用python

Question

因此，我尝试使用ffmpeg

将视频速度更改为其速度的两倍

import paho.mqtt.client as paho
import time


def on_subscribe(client, userdata, mid, granted_qos):
    print('Subscribed')

def on_message(client, userdata, msg):
    mybuffer = str(msg.payload)
    print('on_message: '+ mybuffer)
    print(mybuffer)

client = paho.Client()
client.on_subscribe = on_subscribe
client.on_message = on_message
client.connect('test.mosquitto.org')
client.subscribe('$SYS/#')

client.loop_forever()

当我从winthin命令行运行它时工作正常，并且当我在python模块中运行它时有问题  错误如下：

                          cmd="ffmpeg -i C:\\Users\\Samhita\\Desktop\\EDOS\\D4.mp4 -filter_complex \"[0:v]setpts=0.5*PTS[v];[0:a]atempo=2.0[a]\" -map \"[v]\" -map \"[a]\" 2.mp4"
                          subprocess_call(cmd.split))